If there is a tornado watch or warning, do mailpersons still have to deliver?
During a watch, I would think yes. A watch is valid for typically a six-hour window, with storms or even tornadoes not even guaranteed at any specific locale. Basically a “keep your ears to the radio”.
During a warning, or more generally, any scenario where a thunderstorm is moving in (severe or not), it would depend on the storm, the amount of information the mail carrier has, etc. Safety should always be the first and foremost concern. Occasional rumbles of thunder at 50 degrees in the morning probably isn’t a big deal, but a darkening of the skies during a late spring afternoon could be.
All that said, I don’t know for sure, I’m merely guessing.
Vis
Following on from Viscera’s comments:
Source: http://www.spc.noaa.gov/faq/tornado/
Just a WAG but anyone in a tornado watch area should go about their business but with a heightened sense of awareness. During a tornagdo warning, one should take all necessary safety precautions to protect themselves.
The mail will get through; just not when the pigs are flying by (and the house, the cows, Margaret Hamilton, etc) … 